What is a realistic first strength routine if you have never lifted before?

Three sessions a week, full body, built on a handful of movements rather than a long list: a squat pattern, a hinge, a push, a pull, and something for the core. Two to three sets of five to ten reps each is plenty. Progress by adding a small amount of weight or one rep when the last set still feels controlled. This is deliberately boring — beginners make their fastest progress on simple programmes, and complexity is what makes people quit. Spend the first two weeks learning the movements with light weight rather than testing your limits.